Eat your vitamins

How much would you have to eat to get the nutrients you would get in a daily multivitamin? We examined the nutritional content of a Centrum Adult vitamin and, using USDA information, compared them to the nutritional content of foods that achieve the same. The parentheses contain the percent of Daily Value (DV), which is the Food and Drug Administration's recommended daily intake for each nutrient.

Alexia Elejalde-Ruiz, Tribune Newspapers

Millions of Americans pop a daily multivitamin in hopes of ingesting essential nutrients they worry they're not getting from food. But what if, um, they just got it from food?

"It's much more beneficial to get nutrients in the whole food," said Dr. Eric Rimm, associate professor of epidemiology and nutrition and director of the program in cardiovascular epidemiology at Harvard School of Public Health.

Eating your nutrients the old-fashioned way is preferable to taking vitamins, Rimm said, in part because of how the nutrients are absorbed in the digestive system but mostly because foods contain bioactive compounds that contribute further to overall health. For example, flavonoids, compounds responsible for the colors of various plant-based foods, seem to be very important for lowering blood pressure, but they are not in your standard multivitamin.

Multivitamins historically were created for people who were undernourished or malnourished, Rimm said, so their levels are meant only to get people above a deficient level. Few Americans today are deficient in any essential nutrients, with the exception of Vitamin D among sun-starved people in winter climes, he said. (Recent research suggests people need even more Vitamin D than the recommended daily intake of 400 units, and say the target should be 600 to 1,000 units).

Most people can satisfy their vitamin and mineral needs with a healthy balanced diet without overloading on calories. There is no risk in taking a daily multivitamin on top of a healthy diet, Rimm said, and some studies have shown that long-term multivitamin use reduces the risk of mortality from a number of causes. He does advise people to stay away from megadoses of any vitamin or mineral because that may block the absorption of other important nutrients.